I could go on for quite a while on my problems with this approach. In fact, that theme directly and indirectly runs throughout this blog. So I won't. Instead, I'll offer an analogy.
At increasing speed for the past two decades, highly competitive sports programs have extended their reach into younger and younger age kids. These kids are asked to specialize in the sport; and they undergo longer, more frequent, and more physically demanding training. They--and their families--often do so to pursue visions of long-term and glorious success, i.e. scholarships and even professional contracts. But think for just a moment about how many athletes have even the slightest shot at those levels, let alone make it. For most it's fantasy.
It's a sadder reality that we've since as this trend has emerged. We see a significantly higher percentage of young people suffering injuries, some of them quite serious. Some don't develop their all-around athleticism. Many become burned out in their early teens. Overall, I have to believe the damage outweighs the gains. All this happens because young people are being forced into developmentally inappropriate situations.
It hasn't worked in sports for the overwhelming majority. Why would we expect anything different in academics?